Error Codes - Mitsubishi Electric EHSD-MEC Installation Manual

6
Service and Maintenance

Error Codes

Code Error
L3 Circulation water temperature overheat protection
L4 DHW tank water temperature overheat protection
Indoor unit temperature thermistor (THW1, THW2, THW5, THW6, THW7, THW8,
L5
THW9) failure
L6 Circulation water freeze protection
L8 Heating operation error
L9 Low primary circuit flow rate detected by flow sensor or flow switch (flow switches 1, 2, 3)
LC Boiler circulation water temperature overheat protection
LD Boiler temperature thermistor (THWB1, THWB2) failure
LE Boiler operation error
LF Flow sensor failure
LH Boiler circulation water freeze protection
LJ DHW operation error (type of external plate HEX)
LL Setting errors of DIP switches on FTC control board
J0 Communication failure between FTC and wireless receiver
P1 Thermistor (Room temp.) (TH1) failure
P2 Thermistor (Ref. liquid temp.) (TH2) failure
P6 Anti-freeze protection of plate heat exchanger
J1 - J8 Communication failure between wireless receiver and wireless remote controller
E0 - E5 Communication failure between main remote controller and FTC
E6 - EF Communication failure between FTC and outdoor unit
E9 Outdoor unit receives no signal from indoor unit.
U*, F* Outdoor unit failure
A* M-NET communication error
Note: To cancel error codes please switch system off (Press button E, on main remote controller, for 3 seconds).
Action
Flow rate may be reduced check for;
• Water leakage
• Strainer blockage
• Water circulation pump function (Error code may display during filling
of primary circuit, complete filling and reset error code.)
Check the immersion heater and it's contactor.
Check resistance across the thermistor.
See Action for L3.
Re-attach any thermistors that have become dislodged.
See Action for L3. If the flow sensor or flow switch itself does not work,
replace it.
Caution: The pump valves may be hot, please take care.
Check if the setting temperature of the Boiler for heating exceeds the re-
striction. (See the manual of the thermistors "PAC-TH011HT-E")
Flow rate of the heating circuit from the boiler may be reduced. Check for
• water leakage
• strainer blockage
• water circulation pump function
Check resistance across the thermistor.
See Action for L8. Check the status of the boiler.
Check flow sensor cable for damage or loose connections.
Flow rate of the heating circuit from the boiler may be reduced. Check for
• water leakage
• strainer blockage
• water circulation pump function
• Check for disconnection of DHW tank water temp. thermistor (THW5).
• Flow rate of the sanitary circuit may be reduced.
• Check for water circulation pump function.
For boiler operation, check that DIP SW1-1 is set to ON (With Boiler) and
DIP SW2-6 is set to ON (With Mixing Tank).
For 2-zone temperature control, check DIP SW2-7 is set to ON (2-zone)
and DIP SW2-6 is set to ON (With Mixing Tank).
Check connection cable for damage or loose connections.
Check resistance across the thermistor.
Check resistance across the thermistor.
See Action for L3.
Check for correct amount of refrigerant.
Check wireless remote controller's battery is not flat.
Check the pairing between wireless receiver to wireless remote controller.
Test the wireless communication. (See the manual of wireless system)
Check connection cable for damage or loose connections.
Check that the outdoor unit has not been turned off.
Check connection cable for damage or loose connections.
Refer to outdoor unit service manual.
Check both units are switched on. Check connection cable for damage or
loose connections. Refer to outdoor unit service manual.
Refer to outdoor unit service manual.
Refer to outdoor unit service manual.
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